There are known in the prior art protective helmets and the like which are provided with inner and outer visors which can selectively be moved from an inoperative position to a position in front of the wearer's eyes. Generally, one of the two visors is clear while the other is tinted. Various mechanisms are known for mounting the visors for movement between operative and inoperative positions and for actuating the visors between the two positions. Most of these mechanisms involve the use of tracks mounted on the helmet body, together with individual operating mechanisms for moving the inner and outer visors. Most of the mechanisms also are provided with means for adjusting the visor to intermediate positions in steps.
Luisada et al Pat. No. 3,636,565 shows another form of dual visor assembly in which opposite arms of the respective visors have noncircular openings receiving respective noncircular shafts on opposite sides of the helmet shell. The other visor arms have circular openings receiving the noncircular shafts. Respective positive locking means associated with the shafts are adapted to be released by pushbuttons to permit the shafts to be turned by knobs.
While mechanisms of the type described above are generally satisfactory, they are relatively complicated and bulky. Owing to their complexity, the mechanisms also are relatively expensive to manufacture.